BIOSENSORS FOR NITROGEN CONTROL IN WASTEWATERS

The control of nitrogen removal processes in activated sludge systems requires not only on-line values of the parameters such as ammonium, n itrate and nitrite, but also an evaluation on the nitrifying and denit rifying biomass activity, influent toxicity and carbon source requirem ents for denitrification. This paper describes four different biosenso rs, two on denitrification and two on nitrification. They all measure the biological activity of the nitrifying or denitrifying bacteria. Th ree of them measure nitrogen and carbon species, the fourth biosensor measures influent toxicity. These instruments open new perspectives fo r efficient on-line monitoring of wastewater treatment plants. Copyrig ht (C) 1996 IAWQ.